Automatic stretch bag machine



Nov; 25, 1969 w. s. PEPPLER 3,479,930

AUTOMATIC STRETCH BAG MACHINE Filed Sept. 5, 1967 3 Sheets-Sheet 1 WILLIAM S. PEPPLER 23 KHEL. U) 'FlocKs j ATTORNEY INVENTOR I NW. 25; 3969 w s,: pp 3,479,930

AUTOMATIC STRETCH BAG MACHINE I Filed Sept. 5, 1967 3 Sheets-Sheet 2 POSJTlON Po grlon msrrlom 15', A

POSI'TlON INVENTOR WLLLIAM S. PEPPLER,

QKARL L0 Fwc Kg ATTORNEY Nov. 25, 1969 w. s. PEPPLER 3,479,930

AUTOMATIC STRETCH BAG MACHINE Filed Sept. 5, 1967 3 Sheets-Sheet 5 l /,'4VENTOR WILLIAMS. PEPPLER 1 AQL (A9 FLOCLKS J ATTORNEY United States Patent 3,479,930 AUTOMATIC STRETCH BAG MACHINE William S. Peppler, Chappaqua, N.Y., assignor to Diamond International Corporation, New York,

N.Y., a corporation of Delaware Filed Sept. 5, 1967, Ser. No. 665,364 Int. Cl. B3111 1/32, N64 US. Cl. 938 7 Claims ABSTRACT OF THE DISCLOSURE An automatic stretch bag machine having turret mounted forming bars or spreaders which meet with a film supply fed from a roll and after sealing and cut-otf of the film takes place through the action of a pair of jaws, forming bars, within the bag formed from the film, spread the bag during the rotation of the forming bars and the bag, thereby moving bags successively into positions to be filled.

The present invention relates to bagging machines and has particular reference to an improved bag expanding machine which forms and stretches the bag prior to product insertion.

The conventional method of bagging products makes use of pre-made bags. In addition to the added cost of the bag manufacturing operation, the individual bags are difficult to handle reliably in automatic bagging machines.

At present where a tight, contour fit is desired over the product, bags of stretchable film are manually placed on bag expanding means which stretch the bag prior to product insertion. This type of packing is now commonly used, for example, in poultry packaging.

In the present invention, the method of forming and filling bags is automatically accomplished with the present apparatus which keeps positive control of each bag by forming it over a forming or spreading means that carries it to the product insert position while opening the bag for loading.

Accordingly, the present invention is directed to a method and apparatus for forming a bag from a plastic film which may be supplied in roll form and then automatically expanding this bag while moving it to a position at which a product is inserted therein.

These, as well as further objects and advantages which are inherent to the invention, will become apparent from the following description, reference being had to the accompanying drawings wherein:

FIGS. 1 and 2 are perspective views of one embodiment of a portion of the machine of the present invention during steps in its operation;

FIG. 3 is a partial left side elevational view of a portion of FIG. 1;

FIGS. 4 and 5 are another embodiment of a portion of the machine of the present invention during steps in its operation;

FIG. 6 is a partial top plan view of the portion of the machine in FIG. 5;

FIGS. 7 and 8 are schematic diagrams of front and side views respectively of linkages and gearing for coordinating the movements of the portions of the machine shown in FIGS. 1-6; and

FIG. 9 is a detailed illustration of the Geneva drive viewed along line 9-9 in FIG. 8.

Referring first to the portion of the machine for forming and stretching bags having the embodiment illustrated in FIGS. 1-3, this type of machine is of great help in the handling of clinging type plastic films which are normally used in stretch bag packaging. Such plastic films, because of their clinging quality, can be very troublesome to handle and may not be handled as simply as materials having some rigidity which may be handled by other machines now in use.

As illustrated in FIGS. 1-3 and also in another embodiment shown in FIGS. 4-6, a plurality of pairs of arms 11 and 11' are mounted for rotation on shaft 12. On the outer ends of each of arms 11 and 11 there are located forming bars 15 and 15' respectively, in opposed relationship to each other. Each of forming bars 15 and 15 are pivotally mounted on arms 11 and 11' respectively and comprise jaw elements 16 which are so positioned as to have the jaw elements 16 of each of forming bars 15 and 15 open with these jaws on the forming bars facing each other.

In the embodiment illustrated in FIGS. 1-3, the forming bars 15 and 15 in the form of cantilevered carriers are pivotally mounted on arms 11 and 11 respectively at right angles to those arms. In another embodiment as illustrated in FIGS. 4-6, the forming bars 15 and 15 'are mounted at a different angle to respective arms 11 and 11. In the case illustrated in those latter figures, forming bars 15 and 15 are angled away from respective arms 11 and 11. This angling of the forming bars eliminates the use of picker arm 18 which is used in the embodiment shown in FIGS. 1-3 but not needed in the other embodiment shown in FIGS. 4-6.

A plastic film 20 which may be of a clinging type of film, is supplied from a film supply 21 shown in roll form. This film may be either a single, a single folded, or a double roll of film. If film 20 is in the form of a roll of single film, then it is folded as illustrated in the figures and passes between sealing and cutting jaws 22 where the edge 23 is sealed to form an envelope.

In the embodiment of FIGS. 1-3 after the sealing and cutting operation of jaws 22, picker arm 18 hooks onto an edge of film 20 and pulls this edge back so as to clear the path of entry of forming bars 15 and 15' as shown at position A in FIG. 1. In this position the jaws 16 of forming bars 15, 15 are in a closed or almost closed position.

Forming bars 15 and 15 continue their circular clockwise rotation until forming bar 15 encounters edge 23 which has been sealed. The forming bars 15, 15' then continue past sealing and cutting jaws 22 at the same time advancing film 20 along with the jaw elements 16. At a time after forming bar 15 has passed between sealing and cutting jaws 22, these jaws are clamped together to cut the film and seal another edge so that bars 15, 15 continue with a bag 25 which has just been formed to position B shown in FIG. 2. In timed sequence with the rotation of forming bars 15 and 15' the picker arm 18 returns to the position shown in FIG. 2 so that the film 20 is positioned in this manner for the sealing and cutting jaws 22 which have been activated so as to form the trailing edge seal of bag 25 and at the same time form the leading edge seal on film 20 for the next bag which will be formed.

By the time forming bars 15 and 15 have reached position C, the jaw elements 16 have been opening and at the same time stretching the bag toward an open position. By the time the bag has reached position D, it is opened to its fullest extent with jaw elements 16 in their widest position. At this point, the bag is ready to have a product inserted therein. Either the product may be inserted in a horizontal position and the bag removed from jaws 15 and 15' whereupon its open end will be sealed on another machine, or in this open position bag 25 may be transferred onto a secondary means for product insertion and final sealing. Forming bars 15, 15 then continue their clockwise rotation at the same time closing the jaw elements 16 preparatory to encountering film 20 and repeating the procedure.

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In the embodiment of FIGS. 4-6 the procedure is somewhat similar to that shown in the previous figures. In this form of the machine, with forming bars 15, at an angle of approximately 135 with arms 11 and 11', the need for picker arm 18 is eliminated since due to the angle, forming bars 15 and 15' may enter the folds of film 20 without the necessity of pulling one side of that film out of position. In addition, FIGS. 4-6 have illustrated a variation in the positioning of film supply 21 with the roll now in the horizontal position which necessitates a rotation of all positions illustrated in FIGS. l3 of approximately 90. Therefore, the final loading position is in a different location from that illustrated in FIG. 2 but the loading in this position would still consist of horizontal loading of the products to be inserted. In all other respects the sequence of operation of the forming bars 15, 15' in relation to film 20 and sealing and cutting jaws 22 is the same as previously described.

In order that jaw elements 16 of forming bars 15, 15' may open and close as required and act in conjunction with picker arm 18 in one of the embodiments shown, and with the sealing and cutting jaws 22 both embodi ments, during their rotation about shaft 12, one of the configurations of cams, gears and linkages is shown in FIGS. 7-8. These are merely schematic drawings and do not show construction details of the machine such as stabilizing linkages that would be required to limit the motion of cam rollers to an oscillating radial movement.

As shown in FIGS. 7 and 8 the movement of forming bars 15 and 15 are coordinated by means of their connection to meshed gears 30, 31 which are placed for counter-rotation to each other. Though suitable linkage 32 each pair of meshed gears 30, 31 connected to forming bars 15, 15, are both connected to a single cam roller 33 which rotates on the stationary cam 34. As the arms 11, 11 are rotated, the cam rollers 33 move over high and low points on stationary cam 34 thereby moving the linkages 32 as shown in FIG. 7 so as to rotate gears 31 and thereby cause the rotation of the respective gears meshed therewith. This rotation causes the opening and closing of jaw elements 16.

Shaft 12 upon which are mounted arms 11 and 11 for rotation therewith passes through an opening in stationary cam 34 without any connection thereto. Mounted on shaft 12 for rotation therewith is gear 35. Gear 36 is meshed with gear as illustrated in FIG. 9 and has lever 37 which rotates therewith. Projection 38 on the opposite end of lever 37 from its attachment with gear 36 and shaft 40, moves through an are shown in dashed line to pass into grooves 41 of gear 35. Gears 35 and 36 with lever 37 and projection 38 form a Geneva drive allowing intermittent motion of shaft 40 which rotates once per bag cycle. Mounted on shaft 40 are cams which are a cut and seal cam 41 and a picker arm cam 42 which operate through suitable linkage and cam follower arrangement (not shown). The picker arm cam will operate picker arm 18 in the embodiment of the machine shown in FIS. 1-3. Through linkage as shown in FIG. 8 with a cam follower riding on cut and seal cam 41, cutting and sealing aws of a pivoted type may be operated While other linkage (not shown) operating oil of cut and seal cam 41 alternatively can operate sealing and cutting jaws 22 which are a clamping type of mechanism. It should be apparent that the apparatus described heremg can automatically handle the forming and filling of plastic bags which may be of a clinging type of plastic usually difiicult to handle, with a minimum of difiiculty and transfer of the plastic film.

It will be obvious to those skilled in the art that vanious changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown in the drawings and described in this specification.

What is claimed is: 1. A machine for forming and opening bags made of plastic film comprising a shaft, at least one pair of forming bars mounted for rotation about said shaft, sealing and cutting means connected to operate in conjunction with the rotation of said forming bars, supply means to feed the plastic film to said sealing and cutting means in a double layer of the film, said forming bars positioned to enter between the double layer of plastic film at a position adjacent to said sealing and cutting means, said sealing and cutting means operating to cut and seal the plastic film after passage of a pair of said forming bars in the plastic film past said sealing and cutting means. 2. The machine of claim 1 further characterized by a picker means to grip and separate the double layer of plastic film to enable the movement of said forming bars therebetween. 3. The machine of claim 1 further characterized by arms extending from said shaft and mounted on said shaft for rotation therewith, said forming bars mounted on said extending arms so as to form an obtuse angle with said arms. 4. The machine of claim 1 further characterized by said forming bars each including jaw member elements, said jaw member elements of a pair of said forming bars forming jaws opening in positions facing each other and operating in unison with each other. 5. The machine of claim 4 further characterized by a gear mounted on each said jaw member element, said gears intermeshing to operate the jaw members elements on each forming bar in counter-rotating relationship to each other, a stationary cam mounted within the circle of rotation of said forming bars, cam follower means positioned to ride on said stationary cam, linkage connecting each of said cam follower means to at least one of said gears of one of said jaw member elements of each of said forming bars. 6. The machine of claim 5 further characterized by said linkage connecting each of said cam follower means to at least one of said gears of both of a said pair of forming bars. 7. The machine of claim 5 further characterized by a second shaft parallel to said first-mentioned shaft, cam means to operate said sealing and cutting means mounted for rotation on said second shaft, and intermittent motion gear means mounted on said shafts in operative relation to rotate said second shaft intermittently in relation to the rotation of said first-mentionted shaft.

References Cited UNITED STATES PATENTS 2,754,644 7/1956 Vergobbi et a] 53-29 3,382,644 5/1968 Vogt 53-29 3,379,101 4/1968 Piazze 938 THERON E. CONDON, Primary Examiner E. F. DESMOND, Assistant Examiner U.S. Cl. X.R. 53183 

